MetaClass

GEOS SDK TechDocs

1 Special Messages

MetaClass is the ancestor class of every GEOS object. MetaClass is the location of basic messages and their handlers. Basic functionality for all objects--instantiation, initialization, detach, and destruction--is implemented within this class.

The only instance data field defined for MetaClass is the object's class pointer (the field is named MI_base ). MetaClass has no other inherent data fields. You will never need to access the class pointer directly.

MetaClass also serves as a sort of placeholder for certain messages. Application writers familiar with mouse input, for instance, know that MSG_META_START_SELECT signals a mouse click. This message is actually defined at the MetaClass level, though MetaClass

  1 Special Messages
  2 Utility Messages
    2.1 Object Creation and Destruction
    2.2 Class Messages
    2.3 Object Management Messages
    2.4 User Interface Utility Meta Messages
    2.5 Event Messages
    2.6 Variable Data Messages
    2.7 Notification Messages
    2.8 Options Messages
    2.9 Suspending and Unsuspending
    2.10 Help Files
  3 Exported Message Ranges
    3.1 Window Messages
    3.2 Input Messages
    3.3 UI Messages
    3.4 Standard GCN Messages
    3.5 IACP Meta Messages

GEOS SDK TechDocs

1 Special Messages